Not all permanent magnets are the same. By definition, a permanent magnet is any object that produces a magnetic field without the assistance of an inducing field or electric current. Some of them occur naturally in the Earth’s crust, whereas others are man-made. Regardless, all permanent magnets produce a “permanent” magnetic field that doesn’t require an inducing field or electric current. There are four primary types of permanent magnets, however, each of which consists of a different material.
#1) Neodymium
Neodymium magnets are permanent magnets. Also known as NdFeB and NIB magnets, they consist primarily of neodymium. Neodymium is a rare-Earth metal. It’s typically mixed with iron and boron to create permanent magnets. These magnets are known as neodymium magnets.
Neodymium magnets are among the strongest magnets on the market. They have high magnetic properties and are commonly used in motors, generators, speakers and other products.
#2) Samarium Cobalt
There are permanent magnets made of samarium and cobalt. Known as samarium cobalt magnets, they were originally developed in the 1960s. While working at the Wright-Patterson Air Force Base, Karl Strnat discovered that mixing samarium and cobalt resulted in a super-strong permanent magnet.
#3) Ceramic or Ferrite
Some permanent magnets are made of ceramic or ferrite. They consist primarily of iron oxide, which is mixed with other ceramic materials. They have lower magnetic strength compared to neodymium and samarium cobalt magnets, but are inexpensive and have high resistance to demagnetization. These properties make ceramic or ferrite magnets a popular choice for a variety of everyday products.
#4) Alnico
Alnico magnets are permanent magnets made from a combination of aluminum, nickel and cobalt. They also have a lower magnetic strength when compared to neodymium and samarium cobalt magnets, but they have excellent resistance to high temperatures.
In Conclusion
Most permanent magnets fall under one of four categories: neodymium, samarium cobalt, ceramic or ferrite, or alnico. They are all permanent magnets, so they don’t require an inducing field or electric current to produce a magnetic field. Nonetheless, each of these four permanent magnets has a different composition.
Neodymium magnets are made of neodymium, iron and boron. Samarium cobalt magnets are made of samarium and cobalt. Ceramic or ferrite magnets are made of iron oxide and other ceramic materials. Finally, alnico magnets are made of aluminum, nickel and cobalt. Hopefully, this gives you a better understanding of the four types of permanent magnets.